Heel supporting device for a ski safety binding

ABSTRACT

A heel supporting device which forms a part of a ski safety binding that automatically opens when an excessive force is exerted on the ski boot. The heel supporting device includes heel holding means which comprise a pin secured to a casing, a lever pivotably connected to a supporting member and adjustable spring means for pressing the lever to the pin. The lever has a notch and a curved face contiguous to the notch. The pin is engaged in the notch at a normal position of use and is disengaged from it to release the heel of the ski boot when a strong upward directed force is applied to the heel. When the skier steps down his boot to fit it with the ski binding, the pin slides along the curved face of the lever and engages in the notch without pushing the lever against the force of the spring thereby facilitating connection of the ski boot to the ski binding.

United States Patent Hashioka Sept. 17, 1974 [75] Inventor: NoriyasuHashioka, Tokyo, Japan [73] Assignee: Hope Kabushiki Kaisha, Tokyo,

Japan [22] Filed: Nov. 10, 1972 [21] Appl. No.: 305,614

[30] Foreign Application Priority Data Nov. 25, 1971 Japan 46-94132 [52]US. Cl. 280/11.35 T [51] Int. Cl. A63c 9/08 [58] Field of Search 280/11.35 T

[56] References Cited UNITED STATES PATENTS 3,317,217 5/1967 Poiger280/11.35 T 3,391,944 7/1968 Shimizn 1 2530/1135 T 3,554,571 1/1971Smolka 280/1 1.35 T

Primary Examiner-Robert R. Song Attorney, Agent, or Firm-Diller, Brown,Ramik & Wight 5 7 ABSTRACT A heel supporting device which forms a partof a ski safety binding that automatically opens when an excessive forceis exerted on the ski boot. The heel supporting device includes heelholding means which comprise a pin secured to a casing, a leverpivotably connected to a supporting member and adjustable spring meansfor pressing the lever to the pin. The lever has a notch and a curvedface contiguous to the notch. The pin is engaged in the notch at anormal position of use and is disengaged from it to release the heel ofthe ski boot when a strong upward directed force is applied to the heel.When the skier steps down his boot to fit it with the ski binding, thepin slides along the curved face of the lever and engages in the notchwithout pushing the lever against the force of the spring therebyfacilitating connection of the ski boot to the ski binding.

5 Claims, 4 Drawing Figures HEEL SUPPORTING DEVICE FOR A SKI SAFETYBINDING This invention relates to a heel supporting device which forms apart of a ski safety binding, which is adapted to open automatically andrelease the heel of the ski boot from the ski for protecting the skiersleg when an excessive force is exerted on the ski boot due to a forwardfall of the skier, an unusual operation of the ski and other causes.

Various heel supporting devices have been proposed and used whichcomprise a base plate attached fixedly to a ski, a supporting memberprovided on the base plate, a casing covering the supporting member andbeing pivotably connected thereto, which has a heel supporting memberadapted for engaging the heel of the ski boot at the front end thereofand heel holding means which depress the casing toward the base plate ata closed position of the casing (hereinafter referred to as a normalposition of use) thereby pressing the heel firmly on the ski and releasethe casing upwardly when a strong upwardly directed force occurs.

It is one of the conditions with which a heel supporting device mustcomply that a heel depressing spring which constitutes an element of theheel holding means should have a pressing force which is sufficient tocause the heel supporting device to press the heel of the ski bootfirmly upon the ski and prevent it from releasing during ski operationexcept in the case where an excessive stress is applied to the skibinding due, for example, to a forward fall of the skier. For thispurpose, the critical value of the pressing force which is equal to theminimum value of the excessive force which causes the heel to bereleased from the heel supporting device must be adjusted to a suitablevalue from the standpoint of safety in the event of occurence of theexcessive force as well as that of firm clamping of the heel during thenormal operation of the skis. The prior art heel supporting devices,however, have a problem that the stronger the pressing force of thespring, the greater is force required for stepping the ski boot down tofit it with the ski binding from a state in which the casing is pivotedupwardly and the heel supporting device is at its fully releasedposition (hereinafter referred to as a released position). Accordingly,when the skier who has fallen on a sharp slope and had his boot removedsafely from the binding tries to step his boot down to refit it with thebinding while standing on the sharp slope, he finds difficulty inaffording a sufficient step-down force to the binding if the pressingforce of the spring is strong, such difficulty becoming greaterproportionally to the magnitude of the pressing force of the spring. Thereason for requiring such great force in stepping down the boot is thatthe release of the casing from its normal position of use at a strongupwardly directed force is effected by compressing the spring whichforms an element of the heel holding means and, when the casing hasreached its fully released position, the spring has stretched again tolock the casing at the fully released position. Accordingly, thestep-down action of the ski boot requires pivoting of the casing againstthe force of the spring which has to be once compressed before thecasing reaches its normal position of use. This naturally requires asubstantially great provide a novel heel supporting device of a skisafety binding which has eliminated the above described disadvantage ofthe prior art devices.

It is another object of the invention to provide a heel supportingdevice which satisfies the two mutually conflicting conditions that astrong heel depressing force should be maintained for preventing anunexpected release of the boot during skiing and that connection of theski boot to the binding should be effected at a relatively small force.

In this connection, it is an important feature of the invention that theheel holding means of the heel supporting device comprise a pin securedrigidly to a casing, a lever pivotably connected to a supporting memberand adjustable spring means for pressing the lever to the pin, the leverhaving an end face which is pressed by the spring means, a notch formedin an end face opposite to said end face pressed by the spring means anda curved face which is formed contiguous to the notch and, at thereleased position, coincides substantially with an arcuate path ofmovement of the point of contact between the pin and the lever made bythe pivotal movement of the casing between the normal position of useand the released position or lies radially inwardly of this arcuate pathof movement, the pin being engaged in the notch at the normal positionof use and being disengaged from the notch to release the heel of theski boot when a strong upwardly directed force acts upon the heel, andbeing in contact with the curved face at a position at which thedirection of the force of the spring acting upon the pin issubstantially in alignment with a line connecting the axis of the pinand the axis of the pivot pin of the casing when the heel supportingdevice is at the released position.

According to the above described construction, when the skier steps downhis boot to fit it with the ski binding or connects it manually to thebinding by lifting a handle attached to the casing in a manner to bedescribed later, the pin pivots counterclockwise about the pivot pin ofthe casing without causing the lever to pivot clockwise against thepressing force of the spring as is customary with the prior art heelsupporting devices. Moreover, as the pin is slightly shifted from theabove described aligned position by stepping down of the boot or bylifting of the handle, the counterclockwise pivoting force of the leverimparted by the pressing spring acts upon the pin to pivot itcounterclockwise. Accordingly, the force required in stepping down theski boot is mostly for pushing back springs contained in a forwardpressure imparting means to be described later and the force requiredfor pivoting the casing from the released position to the nomal positionof use is relatively small.

It is another object of the invention to provide a practical heelsupporting device which is of a simple and compact construction. To thisend, the lever which is an element of the heel holding means has anelongated portion which is formed in its end portion with a slot forreceiving the end of a ski pole which is used for pushing the lever soas to cause the lever to pivot clockwise and thereby to release thecasing. Thus, the lever which functions as an element of the heelholding means serves also as a release lever with a result that space issaved and the construction of the device simplified.

lt is another object of the invention to provide a heel supportingdevice which has the lever enclosed by the casing except the portion inwhich the slot for receiving the ski pole is formed so as to prevent acasual and undesirable release of the heel supporting device due, for

example, to an accidental hitting of other skiers ski FIG. 1 is ageneral perspective view of the heel supporting device embodying theinvention;

FIG. 2 is a sectional view of the device showing its normal state ofuse;

FIG. 3 is a sectional view showing a state in which the casing is at itsreleased position; and

FIG. 4 is a sectional view of the forward pressure imparting means.

Referring first to FIG. 1, the heel supporting device includes a baseplate 1 to be attached to the upper surface of a ski. The base plate 1has guides 2,2 along its both side edges and has at its front end aserrated raised-up face 3 in which an elongated slot 4 is formed. Apressing plate 8 is slidable on the base plate 1 in the axial directionthereof and is fixed at a suitable position to the base plate 1 by meansof a screw 5 and a washer 6, the latter having a serrated faceengageable with the serrated face of the raised-up face 3 on itsunderside. The pressing plate 8 has at its rear end two bent portions8a, 8a which serve as supports for two springs 9, 9. The pressing plate8 and the springs 9,9 associated therewith compose forward pressureimparting means 7.

A supporting member 10 is disposed on the pressing plate 8 with thelower side edge portions thereof projecting outwardly to slidably engagein the guides 2. The supporting member 10 has an opening 10a in itslower portion for receiving the springs 9, as is shown in FIG. 2. Thus,the supporting member 10 is arranged to be pushed forward by the forwardpressure imparting means 7 when the device is in the state of normal useso as to hold the ski boot tightly in cooperation with a toe piece (notshown) of the ski binding.

A casing 11 is mounted over the supporting member 10 and is pivotablyconnected thereto by means of a pivot pin 12. The casing 11 is providedon its front end with heel supporting members which include a heeldepressing member 13 and a sole engaging plate 14.

The heel holding means employed in the device according to the inventioncomprise a pin 15 secured rigidly to the casing 11 and projectinghorizontally across the base plate 1, a lever 16 pivotably connected tothe supporting member by means of a pivot 24 and adjustable spring meansgenerally designated by reference numeral 17. The spring means 17consist of a spring 18, an adjusting screw 19 for adjusting the force ofthe spring l8 and a guide cap 20. The lever 16 has an end face 21 whichis in abutting engagement with the guide cap of the spring means 17 andis constantly subject to the resilient force of the spring 19. The lever16 also has a notch 22 formed in an end face opposite to the end facepressed by the spring 19 and a curved face 23 formed contiguous to thenotch 22. At the released position, the curved face 23 coincidessubstantially with an arcuate path of movement of the point of contactbetween the pin 15 and the lever 16 made by the pivotal movement of thecasing between the normal position of use and the released position orlies radially inwardly of this arcuate path of movement.

The lever 16 has an elongated portion 27 which is formed in its endportion with a slot 26 for receiving the end of a ski pole. The lever 16further has a notch 25 formed at the root of the elongated portion 27 insuch a manner that the pivot pin 12 is engaged in it when the device isat the released position. The lever 16 is enclosed by the casing 11except the end portion in which the slot 26 is formed and the topportion adjacent thereto. It will be understood that this constructionis effective for preventing the lever 16 from being accidentally pivotedto release the heel supporting device when, for example, other skiersski strikes against his binding.

The casing 11 is provided at the rear end thereof with a handle or gripportion 28 which enables the skier to move the casing manually from thereleased position to the normal position of use. The lower surface ofthe rear end portion of the casing 11 is in abutting contact with theupper end surface of the lever 16.

Referring to FIGS. 2 and 3, the operation of the heel supporting deviceaccording to the invention will be described. In FIG. 2, the device isat the normal position of use. The heel supporting members 13, 14 holdthe heel of the ski boot and press it forwardly due to the action of theforward pressure imparting means 7. The pin 15 is engaged in the notch22 of the lever 6 and prevents the casing 11 from being pivoted duringthe normal state of use. When a strong upward directed force acts on theheel due, for example, to a forward fall of the skier, the pin 15 tendsto move upwardly and causes the lever 16 to pivot clockwise about thepivot 24 against the force of the spring 18. Accordingly, the pin 15 isdisengaged from the notch 24 and moves upwardly along its arcuate pathof movement about the pivot pin 12. As a result, the casing 11 to whichthe pin 15 is secured is pivoted clockwise and the boot heel isreleased. The release of the boot can also be effected voluntarily byinserting the end of a ski pole into the slot 26 and pushing down thelever 27. The position of the pin 15 is so arranged that when it is atthe released position shown in FIG. 3 it is in contact with the curvedface 23 of the lever 16 at a position at which the direction of theforce of the spring 18 acting upon the pin 15 is substantially inalignment with a line connecting the axis of the pin 15 with the axis ofthe pivot pin 12. At this released position the pivot pin 12 is broughtinto abutting engagement with the notch 25 and further clockwise pivotalmovement of both the lever 16 and the casing 11 is prevented. At thereleased position the lever 16 holds the spring 18 in a compressed stateand therefore is subject to the force of the spring 18. However, the pin15 remains stationary at the released position because the direction ofthe force acting upon the pin 15 is substantially in alignment with theline connecting the axis of the pin 15 with the axis of the pivot pin 12as described above.

For bringing the released condition of the device shown in FIG. 3 backinto the normal state of use shown in FIG. 2, the skier has only to stephis boot heel lightly down onto the sole engaging plate 14 as in theconventional manner, or otherwise he may hold the handle portion 28 ofthe casing 16 by hand and lift it,

whereby the pin is caused to pivot counterclockwise to the normalposition of use. It is to be noted that the curved face 23 substantiallycoincides with the arcuate path of movement of the point of contactbetween the pin 15 and the lever 16 or lies radially inwardly of thisarcuate path of movement. Consequently, the pin 15 smoothly slides downalong the curved face 23 into the notch 22 without causing the lever 16to pivot clockwise and thereby pushing back the spring 18. Thus, thisoperation only requires application of a relatively small force and theskier can set the device at ease by lightly stepping down his boot ormanually bringing the device to the normal use position even in anextremely unfavourable situation such as on a sharp slope.

What is claimed is:

1. In a heel supporting device for a ski safety binding comprising abase plate attached fixedly to a ski, a supporting member provided onsaid base plate, a casing covering said supporting member and beingpivotably connected thereto by means of a first pivot extendinghorizontally across the axis of the ski, heel supporting members fixedlysecured to said casing and adapted for fit-ting with the heel of a skiboot at the front end thereof and heel holding means for pressing saidcasing downwardly toward said base plate at a normal position of use andreleasing said casing upwardly when a strong upwardly directed force isexerted on said casing, the improvement wherein said heel holding meanscomprise a pin secured rigidly to said casing and extending horizontallyacross the axis of the ski, a lever pivotably connected to saidsupporting member below said first pivot by means of a second pivotextending horizontally across the axis of the ski and adjustable springmeans for pressing said lever to said pin, said lever having a rearwardend face being pressed by said spring means, a notch formed in a forwardend face opposite to said rearward end face being pressed by said springmeans and a curved face which is formed contiguous to said notch and, atthe released position, coincides substantially with an arcuate path ofmovement of the point of contact between said pin and said lever made bythe pivotal movement of said casing between the normal position of useand the released position or lies radially inwardly of this arcuate pathof movement, said pin being engaged in said notch at the normal positionof use and being disengaged from said notch to release the heel of theski boot when a strong upwardly directed force acts upon the heel, and,at the released position being in contact with said curved face at aposition at which the line of action of the rotational force caused bythe force of the spring acting at the point of contact between said pinand said curved face is substantially collinear with a line connectingthe axis of said pin and the axis of said first pivot of said casing.

2. A heel supporting device as defined in claim 1 wherein said lever hasan elongated portion which is provided in the end portion thereof with aslot for re ceiving the end of a ski pole.

3. A heel supporting device as defined in claim 2 wherein said lever isenclosed by said casing except the portion in which said slot forreceiving the end of the ski pole is formed.

4. A heel supporting device as defined in claim 1 wherein said casing isprovided at the rear end thereof with a handle for manually pivotingsaid casing from the released position to the normal position of use andfrom the normal position of use to the released position.

5. A heel supporting device as defined in claim 1 wherein said lever hasanother notch in which the pivot of said casing is in abuttingengagement at the released position of the device.

1. In a heel supporting device for a ski safety binding comprising abase plate attached fixedly to a ski, a supporting member provided onsaid base plate, a casing covering said supporting member and beingpivotably connected thereto by means of a first pivot extendinghorizontally across the axis of the ski, heel supporting members fixedlysecured to said casing and adapted for fitting with the heel of a skiboot at the front end thereof and heel holding means for pressing saidcasing downwardly toward said base plate at a normal position of use andreleasing said casing upwardly when a strong upwardly directed force isexerted on said casing, the improvement wherein said heel holding meanscomprise a pin secured rigidly to said casing and extending horizontallyacross the axis of the ski, a lever pivotably connected to saidsupporting member below said first pivot by means of a second pivotextending horizontally across the axis of the ski and adjustable springmeans for pressing said lever to said pin, said lever having a rearwardend face being pressed by said spring means, a notch formed in a forwardend face opposite to said rearward end face being pressed by said springmeans and a curved face which is formed contiguous to said notch and, atthe released position, coincides substantially with an arcuate path ofmovement of the point of contact between said pin and said lever made bythe pivotal movement of said casing between the normal position of useand the released position or lies radially inwardly of this arcuate pathof movement, said pin being engaged in said notch at the normal positionof use and being disengaged from said notch to release the heel of theski boot when a strong upwardly directed force acts upon the heel, and,at the released position being in contact with said curved face at aposition at which the line of action of the rotational force caused bythe force of the spring acting at the point of contact between said pinand said curved face is substantially collinear with a line connectingthe axis of said pin and the axis of said first pivot of said casing. 2.A heel supporting device as defined in claim 1 wherein said lever has anelongated portion which is provided in the end portion thereof with aslot for receiving the end of a ski pole.
 3. A heel supporting device asdefined in claim 2 wherein said lever is enclosed by said casing exceptthe portion in which said slot for receiving the end of the ski pole isformed.
 4. A heel supporting device as defined in claim 1 wherein saidcasing is provided at the rear end thereof with a handle for manuallypivoting said casing from the released position to the normal positionof use and from the normal position of use to the released position. 5.A heel supporting device as defined in claim 1 wherein said lever hasanother notch in which the pivot of said casing is in abuttingengagement at the released position of the device.